JP6171709B2 - Sealed thermal transfer image receiving sheet - Google Patents

Description

  The present invention relates to a seal-type thermal transfer image receiving sheet.

  Excellent thermal transparency, high reproducibility and gradation of intermediate colors, and easy formation of high-quality images equivalent to conventional full-color photographic images. It is widely done. Examples of the printed material on which a thermal transfer image is formed on a transfer object include digital photographs, ID cards, driver's licenses, membership cards, and other ID cards used in many fields.

  For the formation of a thermal transfer image by a sublimation transfer method, a thermal transfer sheet in which a dye layer is provided on one side of a substrate and a transfer target, for example, a thermal transfer in which a receiving layer is provided on one side of another substrate An image receiving sheet is used. Then, by superposing the receiving layer of the thermal transfer image-receiving sheet and the dye layer of the thermal transfer sheet, by applying heat from the back side of the thermal transfer sheet by the thermal head, the dye of the dye layer is transferred onto the receiving layer, A printed matter having a thermal transfer image formed on the receiving layer is obtained. According to such a sublimation transfer method, since the amount of dye transfer can be controlled by the amount of energy applied to the thermal transfer sheet, density gradation is possible, so that the image is very clear and has transparency and halftone. Therefore, it is possible to form a high-quality printed product comparable to a full-color photographic image.

  Recently, as proposed in Patent Document 1, a seal part in which a pressure-sensitive adhesive layer, a base material layer, and a receiving layer are laminated is provided on the surface of a release sheet so as to be peelable from the release sheet. Thermal transfer image receiving sheets are known. According to this thermal transfer image receiving sheet, after a desired image is formed on the receiving layer, the seal portion is peeled off from the release sheet, and the receiving layer on which the image is formed can be applied to an arbitrary object using the adhesive layer. Attention has been increasing in that it can be attached and can be used in a wider range of usage compared to conventional thermal transfer image-receiving sheets. This thermal transfer image receiving sheet may be referred to as a seal-type thermal transfer image receiving sheet depending on its usage.

  At the time of image formation using the above-described seal-type thermal transfer image-receiving sheet, the seal-type thermal transfer image-receiving sheet is conveyed to an image forming position by a conveyance roller or the like included in the printer. Or the like from the printer. Here, when the seal-type thermal transfer image receiving sheet is poorly conveyed during image formation, specifically, when the seal-type thermal transfer image-receiving sheet is not accurately conveyed to the image forming position, image misalignment occurs. Causes degradation of image quality. Therefore, in order to improve the quality of the image formed on the receiving layer of the seal type thermal transfer image receiving sheet, it is important to improve the transportability of the seal type thermal transfer image receiving sheet conveyed to the image forming position.

  Current mainstream printers have a pair of transport rollers, for example, a pinch roller and a capstan roller, downstream of the heat transfer image receiving sheet in the transport direction, and rotate with the heat transfer image receiving sheet sandwiched between the pinch roller and the capstan roller. And a thermal transfer image receiving sheet is conveyed to the image forming position by the rotation (for example, Patent Document 2). The pinch roller is a roller that is brought into contact with the receiving layer on the surface side of the thermal transfer image receiving sheet. As the pinch roller, a roller having a smooth surface or a roller having an uneven surface is known. In the former pinch roller, the entire pinch roller is brought into contact with the receiving layer and pressed. On the other hand, in the latter pinch roller, the convex and concave portions are brought into contact with and pressed into the receiving layer. And grip with pinch rollers. The capstan roller is a roller that comes into contact with the back side of the thermal transfer image receiving sheet, and usually a large number of spikes that are fine protrusions are provided on the surface of the capstan roller. The spike receives a pressure from the pinch roller and bites into the back surface of the thermal transfer image receiving sheet, thereby preventing the thermal transfer image receiving sheet from shifting. Further, the heat-transfer image-receiving sheet after image formation is conveyed to the discharge tray side by a pair of discharge rollers having the same configuration as the above-described transfer roller, and is discharged from the discharge tray. However, with respect to the discharge roller after image formation, since the conveyance load at the time of printing is smaller than that at the time of printing, the pair of discharge rollers may not be processed with uneven shapes or protrusions.

  As with the conventional thermal transfer image receiving sheet, the seal-type thermal transfer image receiving sheet is also required to have improved transportability during image formation. In order to improve the transportability, it is preferable to increase the pressure of the pinch roller that presses the receiving layer of the seal-type thermal transfer image-receiving sheet to increase the grip performance. Specifically, it is preferable to increase the pressure of the capstan roller that presses the release sheet of the seal-type thermal transfer image-receiving sheet so that the spikes possessed by the capstan roller sufficiently penetrate the release sheet. Here, in order to improve the transportability, as described above, the pressure of the capstan roller that presses the release sheet portion of the seal-type thermal transfer image-receiving sheet is increased, and the spike of the capstan roller is released at a high pressure. In the case where it is bitten into the portion, spike marks are generated on the surface of the receiving layer of the seal-type thermal transfer image receiving sheet by pushing up the spikes, thereby causing a reduction in image quality.

  In order to prevent the occurrence of spike marks that may occur on the surface of the receiving layer, it is necessary to reduce the pressure of the pinch roller that presses the seal-type thermal transfer image receiving sheet. However, when the pressure of the pinch roller that presses the seal-type thermal transfer image receiving sheet is lowered, the capstan roller spike cannot sufficiently penetrate into the release sheet of the seal-type thermal transfer image-receiving sheet, and spike marks are generated. Can be prevented, but the transportability is reduced. Even if the pressure of the pinch roller that presses the seal-type thermal transfer image receiving sheet is increased without considering the occurrence of spike marks, the inside of the release sheet If the spikes are not sufficiently fixed and held in step 1, that is, if the fixing and holding force of the spikes in the release sheet is low, the transportability cannot be improved. At present, no proposal has been made on a seal-type thermal transfer image-receiving sheet for the purpose of improving the fixed holding force when the spike marks are generated and the spike marks are bitten.

Japanese Patent Laid-Open No. 2002-2127 JP 2012-144005 A

  The present invention has been made in such a situation, and it is a main object of the present invention to provide a seal-type thermal transfer image receiving sheet capable of preventing the occurrence of spike marks without deteriorating the transportability.

The present invention for solving the above problems includes a release sheet part including a back side base material layer, an adhesive layer from the surface of the release sheet part, a front side base material layer including a layer having heat insulation, and a receiving layer. A seal-type thermal transfer image-receiving sheet having a sealing base material portion laminated in this order, and the sealing base material portion being detachable from the release sheet portion, wherein the back-side base material layer is 2 Of the two or more layers constituting the back side base material layer, the layer located farthest from the seal base material portion has a thickness of 38 μm or more. The specific gravity is 0.7 g / cm ³ or more and 1.3 g / cm ³ or less, and the thickness of the entire back-side base material layer having a laminated structure is 50 μm or more.
In addition, a seal-type thermal transfer image-receiving sheet according to an embodiment includes a release sheet portion including a back-side base material layer, a pressure-sensitive adhesive layer from the surface of the release sheet portion, a front-side base material layer including a layer having heat insulation, A seal-type thermal transfer image receiving sheet provided with a seal substrate portion laminated in this order, and the seal substrate portion being detachable from the release sheet portion, wherein the back-side substrate layer is A single layer configuration or a stacked configuration in which two or more layers are stacked, (A): when the back side substrate layer exhibits a single layer configuration, the thickness of the back side substrate layer of the single layer configuration is 50 μm or more, specific gravity is 0.7 g / cm ³ or more and 1.3 g / cm ³ or less, and (B): when the back-side base material layer has a laminated structure, among the two or more layers, The thickness of the layer located farthest from the seal substrate is 30 μm or more, and the specific gravity is 0.7 g. cm ³ or more 1.3 g / cm ³ or less, and the total thickness of the backside substrate layer exhibits a multilayer structure is characterized in that at 50μm or more.

  According to the seal type thermal transfer image receiving sheet of the present invention, it is possible to prevent the occurrence of spike marks without deteriorating the transportability during image formation. In particular, even when the roller pressure of the printer that presses the seal-type thermal transfer image-receiving sheet is increased in order to cope with the higher speed of the printer, it is possible to prevent the occurrence of spike marks without deteriorating the transportability. .

It is a schematic sectional drawing which shows an example of the seal | sticker type thermal transfer image receiving sheet of this invention. It is a schematic sectional drawing which shows an example of the seal | sticker type thermal transfer image receiving sheet of this invention.

  As shown in FIGS. 1 and 2, the seal-type thermal transfer image-receiving sheet 100 of the present invention has a release sheet portion 10 and a seal base portion 20, and the seal base portion 20 is a release sheet portion 10. It is provided so that it can be peeled off. 1 and 2 are schematic cross-sectional views showing an example of a sealed thermal transfer image receiving sheet 100 of the present invention. The release sheet part 10 includes the back side base material layer 1, and the back side base material layer 1 has a single layer configuration in the form shown in FIG. In the form shown in FIG. 2, the back-side base material layer 1 is formed by laminating two or more layers (in the form shown in FIG. 2, the back-side base material layer 1A and the back-side base material layer 1B are laminated via an adhesive layer. It has a laminated structure. The release sheet portion 10 may be composed only of the back side base material layer 1 (not shown), or may include any layer other than the back side base material layer 1 as shown in FIGS. Good. In the illustrated form, the release sheet portion 10 has a laminated structure in which a release layer 7, a back-side base material layer 1, and a back surface layer 5 are laminated.

  The sealing base material portion 20 is from the surface of the back side base material layer 1 of the release sheet portion 10 (in the form shown in FIGS. 1 and 2, from the surface of the release layer 7 of the release sheet portion 10), and an adhesive layer. 21, the front side base material layer 22 and the receiving layer 23 are laminated in this order. The back side base material layer 1 in the release sheet part 10 and the pressure-sensitive adhesive layer 21, the front side base material layer 22, and the receiving layer 23 in the seal base part 20 are essential components in the seal-type thermal transfer image receiving sheet 100 of the present invention. . In the illustrated form, an optional primer layer 27 is provided between the front side base material layer 22 and the receiving layer 23.

  In the illustrated form, the front-side base material layer 22 includes a layer 22A (hereinafter sometimes referred to as a base material 22A) that functions as a support in the seal base material portion 20, and a heat-insulating layer 22B (hereinafter referred to as heat insulation). The layer 22 </ b> B may be referred to as a layer 22 </ b> B). In addition, the front side base material layer 22 is not limited to the form to show in figure, The function as a support body is provided to the heat insulation layer 22B, and the front side base material layer 22 is made into the single | mono layer structure which consists only of the heat insulation layer 22B. (Not shown). Moreover, when the front side base material layer 22 exhibits a laminated structure, the front side base material layer 22 having the laminated structure may include a plurality of layers 22A that function as a support and a plurality of layers 22B having heat insulation properties. . When the layer 22A functioning as a support and the heat insulating layer 22B are laminated via a primer layer or an adhesive layer, the primer layer and the adhesive layer are also used as the front side base material layer 22. include.

  The pressure-sensitive adhesive layer 21 constituting the seal base material portion 20 is a layer located in the lowermost layer of the seal base material portion 20, and on one surface side of the pressure-sensitive adhesive layer 21, the front-side base material layer 22 and the receiving layer. 23 are stacked in this order. The receiving layer 23 is a layer located on the outermost surface of the seal base material portion 20. Therefore, in the present specification, the term “seal base material part 20” includes the pressure-sensitive adhesive layer 21, the front-side base material layer 22, and the receiving layer 23, and further between the pressure-sensitive adhesive layer 21 and the receiving layer 23. Means a laminate including all layers arbitrarily provided. Moreover, in this specification, when it says the release sheet part 10, the laminated body of all the layers provided in the other surface side of the adhesive layer 21, or the single layer which is an essential layer, or The layer which consists only of the back side base material layer 1 of a laminated structure is meant. Therefore, in the form shown in FIGS. 1 and 2, the laminate of the release layer 7, the back side substrate 1, and the back layer 5 becomes the release sheet portion 10, and the adhesive layer 21, the front side substrate layer 22, and the primer layer 27. The laminated body of the receiving layer 23 becomes the seal base part 20.

<< Release sheet part >>
In the seal-type thermal transfer image-receiving sheet 100 of the form shown in FIGS. 1 and 2, an arbitrary release layer 7 is provided on one surface of the back-side base material layer 1, and an optional back surface on the other surface of the back-side base material layer 1. The layer 5 is provided, and the release sheet portion 10 has a laminated structure in which the release layer 7, the back-side base material layer 1, and the back surface layer 5 are laminated in this order from the seal base material portion 20 side. In addition, the release layer 7 and the back surface layer 5 are arbitrary structures in the release sheet part 10. The back-side base material layer 1 may have a single-layer configuration composed of only one layer, or may exhibit a stacked configuration in which two or more layers are stacked. In the form shown in FIG. 1, the back-side base material layer 1 has a single layer configuration. In the form shown in FIG. 2, the back-side base material layer 1 is the back-side base material layer 1B, the back-side base layer from the seal base material part 20 side. A laminated structure in which the material layers 1A are laminated in this order is presented. In addition, in FIG. 2, although the structure by which back side base material layer 1B and back side base material layer 1A were laminated | stacked is shown, it is not limited to this form, The structure by which another back side base material layer was laminated | stacked You can also take

  The seal-type thermal transfer image-receiving sheet 100 of the present invention can accurately convey the seal-type thermal transfer image-receiving sheet to an image forming position during image formation on a receiving layer using a printer, and can also be used for seal-type thermal transfer image transfer after image formation. In order to prevent the occurrence of spike marks that may occur on the surface of the receiving layer in the image receiving sheet 100, the back-side base material layer 1 has the characteristics described below. Hereinafter, a general printer used in combination with the seal-type thermal transfer image-receiving sheet of the present invention will be described, and then the back-side base material layer 1 of the release sheet portion 10 is composed of only one layer. Specific description will be given separately for a case where a single layer structure is formed and a case where a stacked structure in which two or more layers are stacked is provided.

  A general printer used in combination with the seal-type thermal transfer image-receiving sheet 100 of the present invention has a pair of transport rollers, for example, a pinch roller and a capstan roller, downstream of the seal-type thermal transfer image-receiving sheet in the transport direction. The seal-type thermal transfer image receiving sheet 100 is sandwiched and rotated by a roller and a capstan roller, and the thermal transfer image receiving sheet is conveyed to the image forming position by the rotation. The pinch roller is a roller that is brought into contact with the receiving layer on the surface side of the seal-type thermal transfer image receiving sheet 100. As the pinch roller, a roller having a smooth surface or a roller having an uneven surface is known. Yes. In the former pinch roller, the entire pinch roller is brought into contact with the receiving layer and pressed. On the other hand, in the latter pinch roller, the convex and concave portions are brought into contact with and pressed into the receiving layer. And grip with pinch rollers. The capstan roller is a roller that comes into contact with the back side of the thermal transfer image receiving sheet, and usually a large number of spikes that are fine protrusions are provided on the surface of the capstan roller. This spike is configured to receive a pressure from the pinch roller and bite into the back surface of the seal type thermal transfer image receiving sheet, thereby preventing the seal type thermal transfer image receiving sheet from being displaced.

(Back side base material layer of single layer configuration)
In the sealed thermal transfer image-receiving sheet according to the first embodiment of the present invention, the back-side base material layer 1 included in the release sheet portion 10 has a single-layer structure (see FIG. 1), and the back-side base material having the single-layer structure. It is characterized in that the layer 1 satisfies the following conditions.
Condition 1. The thickness of the back side base material layer 1 is 50 μm or more.
Condition 2. The specific gravity of the back side substrate layer 1 is 0.7 g / cm ³ or more and 1.3 g / cm ³ or less.

  The above feature 1 is a condition mainly for preventing the occurrence of spike marks, and can be generated on the surface of the receiving layer of the seal-type thermal transfer image receiving sheet 100 after image formation by setting the thickness of the back side base material layer 1 to 50 μm or more. This prevents the occurrence of spike marks. In order to cause the capstan roller spike to penetrate into the back side base material layer, the thickness of the back side base material layer may be 30 μm or more, but the thickness of the back side base material layer having a single layer configuration is 30 μm or more and less than 50 μm. In some cases, the back-side base material layer cannot reduce the push-up caused by spikes, and cannot prevent the occurrence of spike marks that may occur on the surface of the receiving layer after image formation. That is, in one embodiment of the present invention, in the back side base material layer 1 having a single layer configuration, the thickness can be 50 μm or more, so that spikes can be surely bited into the back side base material layer 1 during image formation. By reducing the push-up of spikes, the occurrence of spike marks that can occur on the surface of the receiving layer is prevented. In particular, according to the present invention, even when the conveyance speed is increased or the pressure from the capstan roller is increased to cope with high-speed printing of the printer, the occurrence of spike marks is prevented and high-speed printing is performed. It is possible to improve the transportability.

  The term “spike marks” as used in the specification of the present application refers to spikes that have digged into the back side base material layer during image formation and pushed up the back side base material layer and the seal base material side to form a spike on the surface of the receiving layer after image formation. This is a phenomenon in which the protrusion marks remain. Spike marks that can occur on the surface of the receiving layer cause degradation of the quality of the image formed on the receiving layer.

  If the thickness of the back-side base material layer 1 having a single layer configuration satisfies the condition that it is 50 μm or more, the upper limit thickness is not particularly limited, but even if the thickness exceeds 100 μm, no further effect can be expected. , Over spec. Therefore, considering this point, the thickness of the back-side base material layer 1 having a single-layer structure is preferably 50 μm or more and 100 μm or less.

  By the way, in the back side base material layer 1 satisfying the above condition 1, when the spikes are not sufficiently fixed and held in the back side base material layer during transport, the transportability of the seal-type thermal transfer image receiving sheet is lowered and formed. A misalignment occurs in the image, causing a reduction in image quality formed in the receiving layer. For example, when forming an overlapping image on the receiving layer using dyes of each color, if the transportability of the seal-type thermal transfer image-receiving sheet is low, the seal-type thermal transfer image-receiving sheet can be accurately transported to the image forming position. It is impossible to form an image in which the dyes of the respective colors are accurately superimposed. This phenomenon is sometimes referred to as “registration”.

That is, in order to improve the transportability of the seal-type thermal transfer image-receiving sheet, it is important to sufficiently fix and hold the spikes that have bite into the back-side base material layer. In other words, it is important to prevent the spikes from moving freely within the back side substrate layer. In the present invention in consideration of this point, as shown in the above condition 2, the specific gravity of the back-side base material layer 1 is 0.7 g / cm ³ or more and 1.3 g / cm ³ or less. By setting it as the back side base material layer 1 of the single | mono layer structure which satisfy | fills the said conditions 2, the back side base material layer 1 can be made to bite into the back side base material layer 1 reliably, and the said bited-in spike is in the back side base material layer 1 It can be firmly fixed and held.

In addition, when the specific gravity of the back-side base material layer having a single-layer configuration is low, specifically, when it is less than 0.7 g / cm ³ , the bite-in spike should be sufficiently retained in the back-side base material layer. Cannot be carried out, and the spike moves in the back side base material layer, and the transportability is lowered. On the other hand, when the specific gravity of the back-side base material layer having a single layer structure is high, specifically, when it exceeds 1.3 g / cm ³ , it is difficult to cause the back-side base material layer to bite into the spike, and the transportability is reduced. descend.

  The specific gravity of the back side base material layer can be calculated by cutting the back side base material layer into an appropriate size, and determining the volume and the mass of the cut back side base material layer.

  There is no limitation about the material of the back side base material layer 1 of the said single | mono layer structure, A conventionally well-known material can be selected suitably and can be used. As the back-side base material layer 1, for example, stretched or unstretched films of plastics such as polyethylene terephthalate, polyethylene naphthalate and other highly heat-resistant polyester, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyamide, polymethylpentene, Fine paper, coated paper, art paper, cast coated paper, paperboard, emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, cellulose fiber paper, and the like can be mentioned.

  Moreover, the layer which has a micro void inside can also be used as the back side base material layer 1 of a single layer structure. As an example of the layer having a microvoid inside, a polyolefin resin layer having a microvoid inside can be cited. Polyolefin resins such as polyethylene, polyethylene terephthalate, polyethylene naphthalate and other highly heat-resistant polyester, polypropylene, polybutene, polyisobutene, polyisobutylene, polybutadiene, polyisoprene, ethylene-vinyl acetate copolymer, etc. Can be mentioned. Among these, polyester resins and polyolefin resins are preferable materials because the specific gravity can be easily adjusted within the range of the above condition 2.

  As a polyolefin resin layer having microvoids, microvoids (fine vacancies) can be generated inside by the following two methods. One is a method in which inorganic fine particles are kneaded in a polymer, and when the compound is stretched, microvoids are generated using the inorganic fine particles as nuclei. The other is to create a compound blended with an incompatible polymer (one or more types) for the main resin. When this compound is viewed microscopically, the polymers form a fine sea-island structure. When this compound is stretched, microvoids are generated due to separation of the sea-island interface or large deformation of the polymer forming the island.

  Moreover, an arbitrary back surface layer can be provided on the surface of the back side base material layer having a single layer structure on the side not in contact with the seal base material portion. Moreover, an arbitrary back surface primer layer can also be provided between the back side base material layer having a single layer structure and an arbitrary back surface layer. These arbitrary back surface primer layers and back surface layers are layers that do not constitute a back side base material layer. Therefore, the arbitrary back primer layer or back layer does not have to satisfy the above conditions 1 and 2. That is, the back-side base material layer having a single layer structure is sufficient if at least a layer satisfying the above conditions 1 and 2 exists, and the layer present on the outermost surface of the sealed thermal transfer image-receiving sheet is the above condition 1 It does not mean that 2 is satisfied.

  Although the case where the back side base material layer 1 included in the release sheet portion 10 has a single layer configuration has been described above, the seal-type thermal transfer image receiving sheet 100 of the present invention has the back side base included in the release sheet portion 10. The material layer 1 may exhibit a laminated structure in which two or more layers are laminated. In the form shown in FIG. 2, the back side base material layer 1 has a laminated structure in which the back side base material layer 1 </ b> B and the back side base material layer 1 </ b> A are laminated in this order from the seal base material part 20 side. In addition, the back side base material layer 1 of a laminated structure is not limited to the form shown in FIG. 2, and three or more layers may be laminated.

(Back side base material layer of laminated structure)
In the seal-type thermal transfer image-receiving sheet of the second embodiment of the present invention, the back-side base material layer 1 included in the release sheet portion 10 has a single-layer configuration (see FIG. 2), and the back-side base material having the single-layer configuration. It is characterized in that the layer 1 satisfies the following conditions.
Condition A. Condition B. The thickness of the entire back-side base material layer having a laminated structure is 50 μm or more. Among the two or more layers, the thickness of the layer farthest from the sealing base material portion is 30 μm or more, and the specific gravity is 0.7 g / cm ³ or more and 1.3 g / cm ³ or less.

  The feature A is a condition mainly for the prevention of spike marks as in the condition 1 of the seal-type thermal transfer image receiving sheet of the first embodiment. In the back side base material layer 1 having a laminated structure, the back side By setting the thickness of the entire base material layer 1 to 50 μm or more, the occurrence of spike marks that can occur on the surface of the receiving layer of the sealed thermal transfer image receiving sheet 100 after image formation is prevented.

The above feature B is a condition that focuses on making sure that the spike bites into the back side base material layer and sufficiently fixing and holding the spike soaked in the back side base material layer. Specifically, in the back-side base material layer 1 in which two or more layers are laminated, the layer that is farthest from the seal base material portion 20 among the two or more layers constituting the back-side base material layer 1. By satisfying the condition of “30 μm or more” which is one of the above conditions B, the thickness of can be surely spiked into the layer farthest from the seal base material portion 20. Further, the specific gravity of the layer farthest from the seal base material portion 20 satisfies the condition of “0.7 g / cm ³ or more and 1.3 g / cm ³ or less” which is one of the above conditions B. The spiked bite can be fixed and held in a layer farthest from the seal base material portion 20 out of two or more layers constituting the back side base material layer, thereby preventing a decrease in transportability. be able to. For example, in the configuration shown in FIG. 2, the back side base material layer 1 </ b> A located farthest from the seal base material portion 10 among the layers constituting the back side base material layer 1 satisfies the condition B, and the back side base material When the total thickness of the layer 1A and the back-side base material layer 1B satisfies the above condition A, the occurrence of spike marks can be prevented without reducing the transportability.

  Of the layers constituting the back-side base material layer 1, the layer located farthest from the seal base material part 20 is not particularly limited with respect to the upper limit value as long as it satisfies the condition that it is 30 μm or more. The thickness can be appropriately set within a range in which the thickness of the entire back-side base material layer 1 having a laminated structure is 50 μm or more. In addition, the thickness of the layer in the position farthest from the sealing base material portion 20 among the layers constituting the back side base material layer 1 may be 50 μm or more. In this case, regardless of the thicknesses of the other layers constituting the back-side base material layer 1 having the laminated structure, the entire thickness of the back-side base material layer 1 having the laminated structure is 50 μm or more.

  There is no limitation on the material of each layer (1A, 1B in FIG. 2) constituting the back-side base material layer 1 having the above-described laminated structure, and the materials described in the back-side base material layer having the single-layer structure can be appropriately selected. In addition, if the layer in the position farthest from the seal base material portion 20 among the layers constituting the back side base material layer satisfies the above condition B, the layers constituting the back side base material layer in the laminated configuration are the same. The material may be a different material.

  In the seal-type thermal transfer image-receiving sheet 100 of the second embodiment, the layer located farthest from the seal substrate portion 20 satisfies the above condition B in the back-side substrate layer having a laminated structure composed of two or more layers. If so, the other layers (hereinafter referred to as other layers) need not satisfy the condition B. This is because the other layers mainly play a role to prevent the occurrence of spike marks by setting the thickness of the entire back side base material layer to 50 μm or more, and to improve the fixing and holding power of the spikes that have digged into the back side base material layer, The other layers are not affected.

  Further, an arbitrary adhesive layer may be provided between the layers constituting the back side base material layer 1. In the form shown in FIG. 2, an arbitrary adhesive layer 25 is provided between the back side substrate layer 1A and the back side substrate layer 1B. The adhesive layer contains an adhesive and has an adhesive function. Examples of the adhesive component include urethane resins, polyolefin resins such as α-olefin-maleic anhydride resins, polyester resins, acrylic resins, epoxy resins, urea resins, melamine resins, phenol resins, Examples thereof include vinyl acetate resins and cyanoacrylate resins. Among them, a reactive type of acrylic resin, a modified type, etc. can be preferably used. Further, it is preferable to cure the adhesive using a curing agent because the adhesive force is improved and the heat resistance is also increased. As the curing agent, an isocyanate compound is generally used, but aliphatic amines, cycloaliphatic amines, aromatic amines, acid anhydrides and the like can be used.

  In addition, when the adhesive layer 25 is provided, the thickness of the said adhesive layer is also included in the thickness of the back side base material layer 1 whole of a laminated structure.

  The thickness of the adhesive layer 25 is usually about 0.5 μm to 10 μm in a dry state. For the formation of the adhesive layer, generally used coating means can be used, for example, by means of gravure printing, screen printing, reverse roll coating using a gravure plate, etc., It can be obtained by drying. Further, EC sand lamination using polyethylene or the like may be performed.

(Release layer)
As shown in FIG. 1 and FIG. 2, the sealing base material portion 20 is peeled from the release sheet portion 10 on one surface of the back side base material layer 1 (in the illustrated form, the upper surface side of the back side base material layer 1). It is preferable that a release layer 7 for improving the property is provided. The release layer 7 is an arbitrary layer in the seal-type thermal transfer image receiving sheet 100 of the present invention, and is a layer constituting the release sheet portion 10.

  Examples of the resin forming the release layer 7 include waxes, silicone wax, silicone resin, silicone-modified resin, fluorine resin, fluorine-modified resin, polyvinyl alcohol, acrylic resin, heat-crosslinkable epoxy-amino resin, and heat-crosslinkability. Examples include alkyd-amino resins. Further, the release layer may be composed of one kind of resin or may be composed of two or more kinds of resins. The release layer may be formed by using a cross-linking agent such as an isocyanate compound, a catalyst such as a tin-based catalyst, and an aluminum-based catalyst in addition to the releasable resin.

  The thickness of the release layer 7 is generally about 0.1 μm to 5 μm. As a method for forming the release layer, the resin is dissolved or dispersed in an appropriate solvent to prepare a release layer coating solution, and this is applied to the backside substrate layer 1 by a gravure printing method, a screen printing method or It can be formed by applying and drying by a conventionally known means such as a reverse coating method using a gravure plate.

  Further, in place of providing a release layer, a release agent may be included in the back side base material layer 1 so as to impart a release property to the back side base material layer 1 itself. Specifically, when the back-side base material layer 1 having a single-layer configuration is used, a release agent may be contained in the layer. Moreover, when setting it as the back side agent layer which exhibits a laminated structure, among the layers which comprise the back side base material layer 1, the layer in the position nearest to the seal base material part 20, in other words, the seal base material part 20 and A release agent may be contained in the layer in contact.

  Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine or phosphate surfactant, silicone oil, reactive silicone oil, and curable silicone oil. And various modified silicone oils, and various silicone resins.

(Back layer)
As shown in FIGS. 1 and 2, it is preferable that a back surface layer 5 is provided on the other surface of the back side base material layer 1 (in the illustrated form, the lower surface side of the back side base material layer 1). By providing the back surface layer 5, it is possible to further improve the transportability of the seal-type thermal transfer image receiving sheet 100 in combination with the improvement of transportability by the back side base material layer 1. The back surface layer 5 is an arbitrary layer in the seal-type thermal transfer image receiving sheet 100 of the present invention and is a layer constituting the release sheet portion 10.

  Examples of the back layer 5 include resins such as acrylic resins, cellulose resins, polycarbonate resins, polyvinyl acetal resins, polyvinyl alcohol resins, polyvinyl butyral resins, polyamide resins, polystyrene resins, polyester resins, and halogenated polymers. As additives, nylon fillers, acrylic fillers, polyamide fillers, fluorine fillers, polyethylene wax, organic fillers such as amino acid powders, and inorganic fillers such as silicon dioxide and metal oxides are used. can do. Moreover, what hardened | cured these resins with hardening | curing agents, such as an isocyanate compound and a chelate compound, can also be used. The thickness of the back layer 5 is generally about 0.1 μm to 5 μm.

  In addition, as described in the back side base material layer having the single layer configuration, an arbitrary layer such as a back side primer layer or a back side layer is provided on the side of the back side base material layer having the laminated configuration which is not in contact with the seal base portion. Can also be provided. These arbitrary back surface primer layers and back surface layers are layers that do not constitute a back side base material layer having a laminated structure. Therefore, the arbitrary back primer layer or back layer does not have to satisfy the above conditions A and B. That is, there are two or more layers that are in direct or direct contact with the release sheet portion through the adhesive layer, and the total thickness of the indirect or direct contact layers is the above condition. Of the two or more layers satisfying A and satisfying the above condition A, a layer located far from the seal substrate portion only needs to satisfy the above condition B and exists on the outermost surface of the seal-type thermal transfer image receiving sheet. This does not mean that the layer is satisfying the condition B.

<< Seal base material part >>
On the release sheet part 10, a seal base part 20 that can be peeled off from the release sheet part 10 is provided. As the essential layer, the sealing base material portion 20 has a laminated structure in which the pressure-sensitive adhesive layer 21, the front side base material layer 22, and the receiving layer 23 are laminated in this order from the release sheet portion 10 side.

(Adhesive layer)
There is no limitation about the material of the adhesive layer 21, A conventionally well-known solvent type or aqueous adhesive can be used. Examples of the adhesive include vinyl acetate resin, acrylic resin, vinyl acetate-acrylic copolymer, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ethylene acrylic acid copolymer, ethylene-acrylic acid. Examples include ester copolymers, polyurethane resins, natural rubber, chloroprene rubber, and nitrile rubber.

  Considering the improvement in the peelability of the sealing base material part 20 from the release sheet part 10, the adhesive strength of the pressure-sensitive adhesive layer 21 is the peel strength between the release sheet part 10 and the pressure-sensitive adhesive layer 21, and conforms to JIS Z0237. In the peeling method at 180 °, it is desirable that the range is 0.98 to 16.7N, preferably 4.9 to 13.7N. Therefore, in forming the pressure-sensitive adhesive layer 21, it is preferable to use the material and the coating amount as appropriate so that the peel strength is within this range.

  For the pressure-sensitive adhesive layer 21, for example, a pressure-sensitive adhesive layer coating solution obtained by dissolving or dispersing the pressure-sensitive adhesive in an appropriate solvent is used on the release sheet portion 10 by a gravure printing method, a screen printing method, or a gravure plate. It can form by apply | coating and drying by well-known means, such as a reverse roll coating printing method. Although there is no limitation in particular about the thickness of the adhesive layer 21, about 5 micrometers-15 micrometers are preferable.

(Front side base material layer)
As shown in FIGS. 1 and 2, a front-side base material layer 22 is provided on the pressure-sensitive adhesive layer 21. The front-side base material layer 22 is an essential configuration in the seal-type thermal transfer image-receiving sheet 100 of the present invention, and is a layer that constitutes the seal base material portion 20.

  The front-side base material layer 22 is a layer that plays a role of preventing loss of heat applied from the thermal head to the receiving layer 23 and as a support that supports the pressure-sensitive adhesive layer 21 and the receiving layer 23. Therefore, as long as these roles can be fulfilled, the front-side base material layer 22 may have a single-layer structure or a laminated structure. Hereinafter, the front side base material layer 22 will be described with specific examples. The front-side base material layer 22 is not limited to the following examples, and is conventionally known as “heat insulating layer”, “hollow particle layer”, “porous layer”, etc. in the field of thermal transfer image receiving sheets. A layer can be appropriately selected and used. In addition, it is also possible to use a layer obtained by laminating these conventionally known layers and a conventionally known substrate in the field of thermal transfer image receiving sheets.

  As shown in FIGS. 1 and 2, the front-side base material layer 22 of one embodiment has a laminated structure in which a base material 22 </ b> A and a heat insulating layer 22 </ b> B are laminated via an adhesive layer 25. By setting it as a laminated structure, cushioning properties can be improved.

"Base material"
As base material 22A of front side base material layer 22 of one embodiment, stretch of plastics, such as high heat resistance polyester, such as polyethylene terephthalate and polyethylene naphthalate, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyamide, polymethylpentene, etc. Alternatively, an unstretched film, fine paper, coated paper, art paper, cast coated paper, paperboard, and the like can be given.

"Insulation layer"
As the heat insulation layer 22B of one embodiment, a polyolefin resin layer having a microvoid inside can be exemplified. As the polyolefin-based resin layer, those described as “a layer having microvoids” in the back-side base material layer 1 of the release sheet portion 10 can be used as they are, and description thereof is omitted here.

  In the above description, the heat insulating layer having microvoids has been described as an example of the heat insulating layer 22B, but a heat insulating layer having hollow particles can be used instead of the heat insulating layer. As the hollow particles, expanded particles or non-expanded particles can be used. Further, the expanded particles used as the hollow particles may be independent expanded particles or continuous expanded particles. Furthermore, the hollow particles may be organic hollow particles composed of resin or the like, or inorganic hollow particles composed of glass or the like. The hollow particles may be cross-linked hollow particles.

  Examples of the resin constituting the hollow particles include styrene resins such as styrene acrylic resins and cross-linked styrene-acrylic resins, (meth) acrylic resins such as acrylonitrile-acrylic resins, phenolic resins, fluorine resins, and polyamide resins. Examples thereof include resins, polyimide resins, polycarbonate resins, and polyether resins.

  The binder resin is not particularly limited, but usually an aqueous resin that can be dispersed or dissolved in an aqueous solvent is preferably used. Examples of such water-based resins include polyurethane resins such as acrylic urethane resins, polyester resins, gelatin, styrene acrylate esters, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, pullulan, carboxymethyl cellulose, hydroxyethyl cellulose, dextran, dextrin, Polyacrylic acid and salts thereof, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, casein, xanthene gum, locust bean gum, alginic acid, gum arabic, polyalkylenoxide copolymer, water-soluble polyvinyl butyral, Examples thereof include homopolymers and copolymers of vinyl monomers having a carboxyl group or a sulfonic acid group. Moreover, you may use in combination of 2 or more types of the said resin. As the binder resin, for example, when using materials such as gelatin, polyvinyl alcohol, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, etc., these binder resins can also exhibit a cooling gelling function. Separately, a good porous layer can be formed without using a cooling gelling agent described later.

  The amount of the binder resin contained in the heat insulating layer 22B having hollow particles can be appropriately determined depending on the type of hollow particles used and the like, but generally the mass of the binder resin relative to the total solid content of the heat insulating layer 22B. Is preferably 5% by mass to 70% by mass, more preferably 10% by mass to 60% by mass, and particularly preferably 15% by mass to 40% by mass.

(Adhesive layer)
An adhesive layer may be provided between the base material 22A described above and the heat insulating layer 22B. As the optional adhesive layer 25, the adhesive layer described in the back side base material layer having the above-described laminated structure can be used as it is, and detailed description thereof is omitted here.

  In the above description, the front side base material layer 22 has been described by taking a laminated body formed by laminating the base material 22A and the heat insulating layer 22B as an example. You can also

  Although there is no limitation in particular about the thickness of the surface side base material layer 22, It is preferable that it is about 70 micrometers-100 micrometers. The occurrence of curling can be effectively prevented by setting the thickness of the back-side base material layer 1 described above to 50 μm or more and 100 μm or less and the thickness of the front-side base material layer 22 within the above preferable range.

(Receptive layer)
As shown in FIGS. 1 and 2, a receiving layer 23 is provided on the front base material layer 22. The receiving layer 23 is an essential component in the sealed thermal transfer image receiving sheet 100 used in the present invention. The receiving layer 23 contains a binder resin.

<Binder resin>
As the binder resin contained in the receiving layer 23, a conventionally known resin material that can easily receive the dye of the dye layer of the thermal transfer sheet can be used. For example, polyolefin resin such as polypropylene, halogenated resin such as polyvinyl chloride or polyvinylidene chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer or polyacrylate Vinyl resins, polyester resins such as polyethylene terephthalate or polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene or propylene and other vinyl polymers, cellulose resins such as ionomers or cellulose diastases And solvent-based resins such as polycarbonate and acrylic resins.

  Further, in place of the solvent-based resin exemplified above, a water-based resin such as a water-soluble resin, a water-soluble polymer, or a water-based resin can be used as the binder resin. According to the receiving layer 23 of the water-based resin, an image having a high printing density can be formed as compared with the solvent-based receiving layer, and the light resistance and glossiness after the image formation can be improved. .

  Examples of the water-soluble resin and water-soluble polymer include polyvinyl pyrrolidone resin, polyvinyl alcohol resin, and gelatin. Examples of the water-based resin include emulsions such as a vinyl chloride resin, an acrylic resin, and a urethane resin, or a resin in which a part of a solvent such as a dispersion is composed of water. The aqueous resin can be formed, for example, by dispersing and adjusting a solution containing a solvent-based resin by a method such as a homogenizer.

  Further, the receiving layer 23 may contain a release agent for improving the release property with respect to the thermal transfer sheet. As a mold release agent, what was demonstrated as a mold release agent which can be contained in the back side base material layer 1 of the said release sheet part 10 can be used as it is, and detailed description here is abbreviate | omitted.

  The various binder resins described above are preferably contained in an amount of 50% by mass or more based on the total solid content of the receiving layer 23. In particular, by setting the content of the water-soluble resin, water-soluble polymer, or water-based resin within the above range, high gloss can be imparted to the formed image. The same applies to the case of using other binder resins.

  The method for forming the receiving layer 23 is not particularly limited, and the binder resin described above and various additives added as necessary are dissolved or dispersed in an appropriate solvent such as water or a solvent to form a receiving layer. A coating liquid can be prepared, and this can be formed by coating and drying on the front substrate layer 22 by means such as a gravure printing method, a screen printing method, or a reverse coating method using a gravure plate.

  The thickness of the receptor layer is not particularly limited, but is generally about 1 μm to 10 μm.

  The thickness of the entire seal-type thermal transfer image receiving sheet 100 is not particularly limited and can be set as appropriate according to the printer used in combination with the seal-type thermal transfer image-receiving sheet of the present invention. It is preferable that it is 170 micrometers or less.

  The seal-type thermal transfer image-receiving sheet of the present invention has been described above. However, the seal-type thermal transfer image-receiving sheet of the present invention can be variously modified without departing from the spirit of the present invention. Further, the seal-type thermal transfer image-receiving sheet of the present invention may be a long-sheet-like seal-type thermal transfer image-receiving sheet or a seal-type thermal transfer image-receiving sheet wound up in a roll shape. Moreover, a sheet-like seal-type thermal transfer image receiving sheet may be used. Moreover, you may take forms other than this.

  Hereinafter, the present invention will be described with reference to examples and comparative examples. “Part” in the text is based on mass unless otherwise specified.

In forming the seal-type thermal transfer image-receiving sheet of each Example and Comparative Example, the following front side base material layers (1-1) and (1-2) and back side base material layers (1-1) to (1- 9) was prepared.
"Front side base material layer (1-1)"
・ Polyethylene terephthalate film with microvoids (K1212, thickness 75μm Toyobo Co., Ltd.)
"Front side base material layer (1-2)"
・ Biaxially stretched polypropylene film (FOS-BT Thickness 30μm Futamura Chemical Co., Ltd.)
"Back side base material layer (1-1)"
・ Polyester resin film (S100-38 thickness 38μm Mitsubishi Plastics)
"Back side base material layer (1-2)"
・ Polyester film (G1212, thickness 50μm Toyobo Co., Ltd.)
"Back side base material layer (1-3)"
・ Polyester film (G1212, thickness 100μm Toyobo Co., Ltd.)
"Back side base material layer (1-4)"
・ Polyethylene terephthalate film with microvoids (G2311 thickness 38μm Toyobo Co., Ltd.)
"Back side base material layer (1-5)"
・ Polyethylene terephthalate film (E5001 Thickness 100μm Toyobo Co., Ltd.)
"Back side base material layer (1-6)"
・ Biaxially stretched polypropylene film (FOS-BT, thickness 60μm, Futamura Chemical Co., Ltd.)
"Back side base material layer (1-7)"
・ Polyethylene film (L Smart 60μm thickness Mitsui Chemicals Tosero Co., Ltd.)
"Back side base material layer (1-8)"
・ Synthetic paper made of stretched polypropylene film containing inorganic filler (Yupo FPG60, thickness 60μm, Oji Oil Co., Ltd.)
"Back side base material layer (1-9)"
・ Polyethylene terephthalate film with microvoids (P4216, thickness 60μm Toyobo Co., Ltd.)

Example 1
The laminated body which laminated | stacked the said front side base material layer (1-1) and the said front side base material layer (1-2) using the gravure printing method and dry lamination was formed, and the front side base material of the said laminated body On the layer (1-1), a primer layer coating solution having the following composition was applied to a thickness of 1.0 μm when dried to form a primer layer. Next, a receiving layer coating solution having the following composition is applied on the primer layer so as to have a thickness of 4.0 μm when dried, and the receiving base layer / primer layer / receiving layer is formed into a receiving layer. A laminate A laminated in order was obtained.

  Then, the back side base material layer of the laminated structure which laminated | stacked the back side base material layer (1-1) and the back side base material layer (1-6) using the gravure printing method and dry lamination was prepared, and the said back side base material On the layer (1-1), a release layer coating solution having the following composition was applied to a thickness of 0.3 μm when dried to form a release layer. Next, a pressure-sensitive adhesive layer coating solution having the following composition is coated on the release layer so as to have a thickness of 10.0 μm when dried, to form a pressure-sensitive adhesive layer. Back side substrate layer / release layer / The laminated body B by which the adhesive layer was laminated | stacked in this order was obtained. Next, the laminate A and the laminate B are bonded so that the adhesive layer of the laminate B and the front substrate layer of the laminate A face each other, and the back substrate layer / release layer / adhesive layer A laminate C was obtained in which / front surface base material layer / primer layer / receptive layer was laminated in this order. Finally, the back primer layer coating liquid having the following composition is applied to the back side base material layer of the laminate C on the non-release layer side so as to have a thickness of 0.5 μm when dried. Formed. Next, a back surface layer coating solution having the following composition was applied on the back surface primer layer so as to have a thickness of 0.5 μm when dried. Thus, the seal-type thermal transfer image receiving sheet of Example 1 in which the back layer / back primer layer / back substrate layer / release layer / adhesive layer / front substrate layer / primer layer / receiving layer are laminated in this order. Got. Table 1 shows the thickness of the entire back side base material layer, the thickness of the back side base material layer farthest from the seal base material part, and the specific gravity. The same applies to the following examples and comparative examples. In addition, Examples 4 and 5 and Comparative Examples 1 and 2 are back side base material layers having a single layer structure, and Table 1 shows the thickness and specific gravity of the back side base material layer having the single layer structure.

<Primer layer coating solution>
・ Urethane resin 14 parts ・ Titanium oxide 28 parts ・ Toluene 13 parts ・ Methyl ethyl ketone 34 parts ・ Isopropyl alcohol 11 parts

<Coating liquid for receiving layer>
・ 12 parts of vinyl chloride-vinyl acetate copolymer (# 1000A Denki Kagaku Kogyo Co., Ltd.)
・ 0.8 parts of epoxy-modified silicone (X-22-3000T Shin-Etsu Chemical Co., Ltd.)
Amino-modified silicone 0.24 parts (X-22-1660B-3 Shin-Etsu Chemical Co., Ltd.)
・ Toluene 30 parts ・ Methyl ethyl ketone 30 parts

<Release layer coating solution>
・ 100 parts of addition polymerization silicone (KS847H Shin-Etsu Chemical Co., Ltd.)
・ 200 parts of toluene

<Coating liquid for adhesive layer>
・ Acrylic copolymer 48 parts (SK Dyne 1310L Soken Chemical Co., Ltd.)
・ Epoxy resin 0.36 parts (Hardening agent E-AX Soken Chemical Co., Ltd.)
・ Ethyl acetate 51.64 parts

<Backside primer layer coating solution>
・ 100 parts of urethane resin (OPT Primer Showa Ink Industry Co., Ltd.)
・ Isocyanate curing agent 5 parts (OPT curing agent Showa Ink Industry Co., Ltd.)

<Coating liquid for back layer>
・ Vinyl butyral resin 10 parts (Denkabutyral 3000-1 Denki Kagaku Kogyo Co., Ltd.)
・ Silicon dioxide 0.75 parts (Silicia 380 Fuji Silysia Chemical Co., Ltd.)
・ Titanium chelate 0.117 parts (AT chelating agent Denka Polymer Co., Ltd.)

(Example 2)
A sealed thermal transfer image-receiving sheet of Example 2 was obtained in the same manner as in Example 1 except that the back-side base material layer (1-6) was changed to the back-side base material layer (1-7).

(Example 3)
A sealed thermal transfer image receiving sheet of Example 3 was obtained in the same manner as in Example 1 except that the back side substrate layer (1-6) was changed to the back side substrate layer (1-8).

Example 4
A single layer using the back side base material layer (1-2) instead of the back side base material layer having a laminated structure in which the back side base material layer (1-1) and the back side base material layer (1-6) are laminated. A sealed thermal transfer image-receiving sheet of Example 4 was obtained in the same manner as in Example 1 except that the back-side base material layer having the configuration was used.

(Example 5)
A single layer using the back side base material layer (1-3) instead of the back side base material layer having a laminated structure in which the back side base material layer (1-1) and the back side base material layer (1-6) are laminated. A sealed thermal transfer image receiving sheet of Example 5 was obtained in the same manner as Example 1 except that the back side base material layer having the configuration was used.

(Example 6)
A sealed thermal transfer image-receiving sheet of Example 6 was obtained in the same manner as in Example 1 except that the back-side base material layer (1-6) was changed to the back-side base material layer (1-2).

(Example 7)
A sealed thermal transfer image-receiving sheet of Example 7 was obtained in the same manner as in Example 1 except that the back-side base material layer (1-6) was changed to the back-side base material layer (1-3).

(Example 8)
Except for changing the back side base material layer (1-1) to the back side base material layer (1-2) and changing the back side base material layer (1-6) to the back side base material layer (1-4), A seal-type thermal transfer image receiving sheet of Example 8 was obtained in the same manner as Example 1.

(Comparative Example 1)
A single layer using the back side base material layer (1-4) instead of the back side base material layer having a laminated structure in which the back side base material layer (1-1) and the back side base material layer (1-6) are laminated. A sealed thermal transfer image-receiving sheet of Comparative Example 1 was obtained in the same manner as Example 1 except that the back side base material layer having the configuration was used.

(Comparative Example 2)
A single layer using the back side base material layer (1-5) instead of the back side base material layer having a laminated structure in which the back side base material layer (1-1) and the back side base material layer (1-6) are laminated. A sealed thermal transfer image receiving sheet of Comparative Example 2 was obtained in the same manner as in Example 1 except that the back side base material layer having the configuration was used.

(Comparative Example 3)
A sealed thermal transfer image receiving sheet of Comparative Example 3 was obtained in the same manner as in Example 1 except that the back side base material layer (1-6) was changed to the back side base material layer (1-9).

(Evaluation of spike marks)
The seal-type thermal transfer image-receiving sheets of the examples and comparative examples obtained above were combined with a printer (S3195 Sinfonia Technology Co., Ltd.) to print a portrait and the state of spike marks on the surface of the seal substrate. It confirmed visually and evaluated roller trace based on the following evaluation criteria. The evaluation results are shown in Table 1.
"Evaluation criteria"
○: Spike marks are extremely thin and no problem level ×: Spike marks are conspicuous and quality is a problem

(Evaluation of transportability)
The thermal transfer image-receiving sheets of each of the examples and comparative examples obtained above were combined with a printer (S3195 Sinfonia Technology Co., Ltd.), 50 sheets were printed, and it was visually confirmed whether or not there was any registration error. The transportability was evaluated based on the following evaluation criteria. The evaluation results are shown in Table 1. Note that the term “registration” refers to a phenomenon in which a superimposed image is displaced. In addition, the absence of registration means that the transportability is good.
"Evaluation criteria"
○: No registration error occurred in the printed material.
Δ: Some misregistration that lowers the print quality occurs in the printed matter.
X: A large registration error occurred in the printed matter.

  As is clear from Table 1, the layers in the farthest position from the sealing base material portion among the layers constituting the back side base material layer satisfy the above conditions A and B in Examples 1 to 3 and 6 to 8. According to the seal-type thermal transfer image-receiving sheet and the seal-type thermal transfer image-receiving sheets of Examples 4 and 5 in which the back-side base material layer having a single layer structure satisfies the above-described conditions 1 and 2, spike marks can be obtained without reducing the transportability. We were able to confirm that the occurrence of On the other hand, spike marks were generated in the sealed thermal transfer image receiving sheet of Comparative Example 1 in which the back side base material layer having a single layer structure did not satisfy the above condition 2. Further, in the sealed thermal transfer image-receiving sheet of Comparative Example 2 in which the back-side base material layer having a single layer structure did not satisfy the above condition 1, the transportability was lowered and a registration error occurred. Further, among the layers constituting the back side base material layer, the layer located farthest from the seal base material portion does not satisfy the above condition B. In the sealed thermal transfer image of Comparative Example 3, the transportability is reduced and a large registration error occurs. . Also from this result, the superiority of the seal-type thermal transfer image receiving of the present invention is clear.

DESCRIPTION OF SYMBOLS 100 ... Seal thermal transfer image receiving sheet 10 ... Release sheet part 1 ... Back side base material layer 1A, 1B ... Layer 5 which comprises back side base material layer which exhibits laminated structure ... Back surface layer 7 ... Release layer 20 ... Seal base material part 21 ... Adhesive layer 22 ... Front side base material layer 23 ... Receiving layer 25 ... Adhesive layer 27 ... Primer layer

Claims (1)

A release sheet part including a back side base material layer, a pressure sensitive adhesive layer from the surface of the release sheet part, a front side base material layer including a layer having heat insulation, and a seal base material part in which a receiving layer is laminated in this order; A seal-type thermal transfer image-receiving sheet provided such that the seal substrate portion can be peeled from the release sheet portion,
The backside substrate layer exhibits a multilayer structure in which two or more layers are stacked,
Of the two or more layers constituting the back side base material layer, the layer farthest from the seal base material portion has a thickness of 38 μm or more and a specific gravity of 0.7 g / cm ³ or more and 1.3 g / cm ³ or less, and the and seal type thermal transfer image-receiving sheet, wherein the thickness of the entire backside substrate layer exhibits a multilayer structure is 50μm or more.

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